By any chance does your Crescendo say anything (look inside the hole of the body) regarding "Tippin Guitars" or "Bill Tippin" by chance? If not, do you see any serial numbers anywhere on the guitar?
If you can answer yes to any of these, it's your lucky day.
Bill Tippin is a custom Luthier that builds some of the most distinctive and valuable handmade guitars ever produced. (Classed with Martin, Taylor, etc.....)
A Tippin "Crescendo" would run approx. $12,000 + these days..............
If you have a vintage model (Tippin started back in the late 70's), get it appraised..................
Good luck.....................................................